Complete Strategic Guide: Passing the RBQ 1.6 Exam — Contractor, Underwater Civil Engineering

1. What is the RBQ 1.6 licence and who needs it?

Sub-category RBQ 1.6 — Contractor, Underwater civil engineering lets its holder act as the qualifying officer (répondant) for submerged civil engineering works. In Québec, no one may act as a building contractor without a current RBQ licence (Building Act, s. 46), and to obtain the 1.6 sub-category you must pass its qualification exam. This guide, and the full course on Prof-RBQ.ca, cover exactly what that exam tests.

2. Scope of the licence: what work does it authorize?

The 1.6 licence authorizes submerged civil engineering works relating to water intakes, sewer outfalls, bridge piers and caissons, together with similar or related work: cofferdams, dykes and dams other than for power generation, reservoirs and retention basins, canals, jetties, breakwaters, moles, locks and boat ramps, dredging of ports, canals and seaways, and the anchoring of booms and floating docks. When the work concerns such a submerged structure, the holder may also carry out the structural sub-classes 3.1 (concrete), 4.1 (masonry), 5.1 (steel and precast) and 6.1 (wood). Generating-station dams and stand-alone buildings unconnected to a civil work fall outside the sub-category.

3. RBQ 1.6 exam format: what to expect

• Question type: multiple choice (MCQ)
• Duration: 3 hours (180 minutes)
• Passing grade: 60 %
• Languages: French or English
• Scope assessed: 9 modules, 69 competency elements (about 225 required skills)
• Question mix on Prof-RBQ.ca: comprehension and application, mini-cases, exam traps and calculation questions

4. Documentation at the exam: open-book vs closed-book

The RBQ 1.6 exam is closed-book. Only a calculator, ruler, paper and pencil are provided — no legal text or standard is handed out. Every document below is recommended reading you must study and remember.

Documents provided at the exam (open-book)

• None — the exam is closed-book; no reference documents are provided.

Documents to study and memorize (closed-book)

• Building Act (B-1.1) & Reg. professional qualification (B-1.1, r. 9) — Licence requirement (s. 46), categories and the scope of sub-category 1.6.
• Civil Code of Québec — Contracts and the five-year solidary liability for loss of the work (art. 2118).
• Criminal Code (s. 217.1) — Duty of anyone directing work to take reasonable steps to prevent bodily harm.
• Professional Engineers Act (I-9) & R-20 — Reserved engineering acts; construction-industry labour relations and trades.
• Environment Quality Act (Q-2) and its regulations — Ministerial authorization to work in water (s. 22); wetlands, wastewater, shorelines, contaminated soil.
• Species, heritage, wildlife and water Acts — E-12.01, C-61.01, A-18.1, C-61.1, R-13 — when a project touches protected habitats or watercourses.
• Dam Safety Act (S-3.1.01) — Safety rules for the non-power dams that 1.6 may build.
• Regulation on concrete pumps and distribution masts (S-2.1, r. 9) — Prevention rules for concrete pumps used on submerged pours.

5. The 9 modules of competencies

Module 1 — Definitions and principles

Intakes, outfalls, piers, caissons, cofferdams, sheet piles, cathodic protection, buoyancy, soils, foundations, concrete and steel materials.

Module 2 — Types of works authorized by 1.6

Retaining and water-control works, dykes and non-power dams, anchoring, dredging, intakes and outfalls, bridge piers and structural types.

Module 3 — Legislative, normative and regulatory framework

Law vs regulation vs standard, the Building Act, responsibilities, the Engineers Act, R-20, the environmental corpus and the Dam Safety Act.

Module 4 — Execution phases of a submerged project

Sustainable design, permits and authorizations, planning around the open-water window, quality control, site layout and the good-practice rules.

Module 5 — Strength of materials and load transfer

Geotechnics, the five actions, stress and moments, loads and the load path, bracing, structural resistance and heavy-lift safety.

Module 6 — Reading and interpreting drawings and specifications

Plans and specs, order of priority, the geotechnical report, tide and current tables, and project difficulties.

Module 7 — Cost estimation and bidding

Quantity take-off, bulking and tonnage, the special cost drivers of underwater work, and subcontractor selection.

Module 8 — Health & safety on submerged sites

The Safety Code, the high-risk classification of underwater/hyperbaric work, hazard control, the prevention program and monitoring.

Module 9 — Management of construction activities

Management information, supply, preventive maintenance and calibration, procurement principles, quality and technical evaluation.

6. Key competencies and technical requirements (official context)

Buoyancy and uplift: the force you fight on every submerged element

Archimedes' principle (buoyant force F_b = ρ × g × V) governs submerged work. An empty box caisson or a dewatered cofferdam is pushed up by the weight of displaced water and must be ballasted or anchored; underestimating uplift is a classic cause of failure. The exam expects you to compute and reason about this — for example, a 20 m³ caisson experiences roughly 196 kN of buoyant force in fresh water.

Cofferdams, tremie concrete and cathodic protection

Submerged construction has its own methods: a cofferdam is a temporary, dewatered enclosure (not a permanent caisson); underwater concrete is placed by tremie without vibration using an anti-washout mix; and steel is preserved by cathodic protection (sacrificial anode or impressed current), working together with adequate concrete cover.

Environmental authorization before working in water

Under the Environment Quality Act (Q-2, s. 22), a ministerial authorization is required before carrying out work in a watercourse or wetland. Dredging stirs up turbidity and may disturb contaminated sediment, engaging the Q-2 regulations on wetlands compensation, wastewater works and shoreline protection — a real cost and schedule driver.

Five-year liability and the role of the engineer

Article 2118 of the Civil Code makes the contractor, engineer and architect solidarily liable for the loss of the work for five years, including loss from the unfavourable nature of the ground — directly relevant to submerged foundations. Design, reserved calculations and the sealing of plans belong to the engineer (Professional Engineers Act, I-9); the contractor builds to the sealed documents.

A legally high-risk worksite

The Safety Code for the construction industry (s. 2.1) classifies work carried out underwater or in a hyperbaric environment as a high risk construction site. Diving, drowning, hypothermia and decompression govern the safety plan, and a written prevention program is mandatory from 10 workers on site.

7. Preparation strategy and tips to succeed

Because the exam is closed-book across a broad 9-module scope, the winning approach is to study module by module, memorize the key numbers (passing grade 60 %, prevention program from 10 workers, transmission to the CNESST from 20, five-year liability), and practice the calculations (buoyancy, stress and moments, quantity take-off with bulking and tonnage) until they are automatic. Test yourself repeatedly and review the exam traps. Prof-RBQ.ca structures this whole path for you.

8. Why Prof-RBQ.ca is the best way to prepare

Prof-RBQ.ca is the only preparation built directly on the official RBQ competency profile for sub-category 1.6, in English, with every legal citation given by its official English title and article reference. You get 24 structured lessons covering all 69 competency elements, a 168-question bank, a 12-question demo, an image-based visual quiz and flashcards — all online, all aligned to what the exam actually tests.

Frequently asked questions